In 2014, 43 students from Ayotzinapa Rural Teachers’ College disappeared after they were abducted in Iguala, Mexico. More than five years after their disappearance, the families of the students are still fighting for justice. The story is the subject of a stunning new documentary by the world-renowned Chinese artist and activist Ai Weiwei. The film, “Vivos,” follows the families of the disappeared students in their daily lives as they grapple with the absence of their loved ones and attempt to hold the Mexican government accountable for their disappearance. We sat down with Ai Weiwei earlier this week at the Sundance Film Festival in Park City, Utah, to speak with him about “Vivos,” why his next project will focus on Hong Kong, and more.